SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f9ceea6b2669ca796168c9af2455d19f56074626b67312f2d6a21222b028645' 
  AND token = 'LqYm0hByoa3OdfLSUGuxsiOa8ykKg9DtQmOWffGlp8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}