SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0169b45d177dcb3bb13ce6dc614cb37038d731808bae18700eacb4520884a7b' 
  AND token = 'h/DFalw0863joxreOwS/OoF+wJ2X9WRRu2B269auVw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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