SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73d29381023068cf3ce5ecb0dc215f6f4694bc11fb14582aa1e194c58b91637d' 
  AND token = 'wILIXh26I8Vrm2qIPgjxRb5v4fljBpijK3iukuBA3Mc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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