SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ea256697001dfefa3f62bd55708c2a21619e7a42983501d30e22a647d2752a' 
  AND token = 'o35J8Jw2wO7KRPkDSUn20ntYr0iU8SnlvXr8Kj0yw2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}