SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3876cc8a1953e5eeb7d406ba3c4d251a2ee5834edf13781d76f391c5230bf466' 
  AND token = '3dmWXX55TLn3QQYh6zHBlI9Zow3bmhBPz2Gx3CplfWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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