SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8379b80589f8880fe8e2ab06dee0ab926d36503887cc4ef716f90310d70e2f06' 
  AND token = 'SyP5r16QyL2JLzJ5d2Up8RLbyRjX7dMGZIDXG81pjF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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