SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a0d3097de134a680cb9e1c4dba3c13f0d726d7eaea873906c44095458250477' 
  AND token = 'CFVaP4w2NIFFbfcBuwHZjjUwx0g6n6717DO+P9mE1AQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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