SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce84056954bc4a2f5c1c519b20d7394d3bb5761c8af0f9eee9ba507918d26fc7' 
  AND token = 'X7A9yUYY7Bp+Gj5gN2Pd+sBNrUwrFw4W6JwA2Q/4JR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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