SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a0984942578da89da20ac0ed94bd8e18b5b9828605a68983ac05d61e4d1b214' 
  AND token = 'y5dlWvxzp04NUjWvLD9CFI27UIx39jx+WegqCG8RBks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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