SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5791b576d7dc8743f973301ba1c0d564754de0fe73d7adac366ac7867f9ff7a0' 
  AND token = 'kqNoSroINM08lmyR/fGGbIerjHWMWlutNGGU1f81MY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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