SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f715bcf98e31490f883b8876d2672ab774ffdd7e9032c0725c2d7e0eddb1888' 
  AND token = 'nDtsyA8DHfso+hwKTlEgirn25fTvi+kZAEfQKiWq7Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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