SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b148a0dc287394619eb11173d8d89a9b20a4747593761f29f63df07d674bfca5' 
  AND token = 'qQLG3IJ1daDctQp2Km4DiCtWCGwGU+4MhBV9jTsbJZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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