SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97b3ebf9e05b39428d47229aa8a3eb321ced7c09e3ed610ed6692f3d117888e6' 
  AND token = 'LaMlBn7xnz/xfVTY1VZ/vCIHkestiv8Vb72KnZQR8x0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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