SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '138021edb1aa1620abffc7b38a62b0c17aa0672af5b639178a424e182dc57189' 
  AND token = 'MtG4ugosaWQR3OY7qMF9iFux0G8i0En4eIRvqL0B8oQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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