SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f194ffcf7a2ade9b9f80bf548e9da1f1dcccfd32c9cfccbfce37eca9551da33e' 
  AND token = 'IcCRNw+Wgu5EZvGXyPwHI75d2V6Zlp1BQ9JOmB8Gr0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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