SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'feb2c798d02afb37af9a06a1896c0b912cf6fa5ba77af068370fc667a3d45145' 
  AND token = '9WxTF9isrj2jjQ6qp0st9gdyGzOBetN0b1U2hR+J/SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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