SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c86be2d88f6cff64bfc904b376daca7ca7089d24d29570e25f1da7e4ce11c3a5' 
  AND token = 'l5JwVDru1zwZHCqQ3q5ilJvPzSHBlyT4NaaBIIJx6t8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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