Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a7657b420296121abee23aba08c9b67be93b0922eea70c0d5a089de31b92b4e' 
  AND token = '49b/GGnQgVTZkl2236MEklZLw4dGm5WRc0WqZ7eCJvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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