SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ce61248d0919298292598ec0ceabbaebb422d898817f16bd88ed3bdc1a5911d' 
  AND token = 'n8dIaMv8X1qHvULXw1nlkTUD7WVeAbZg+iCNkgEfE30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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