SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b27063dcd627a32168916ec52c46f2d880d50bb88fa639f2cdf66ee9cb3dc4d' 
  AND token = 'SndyuCozzZn639T4uJXcN14FHFmgpMEAVkmza1OSGdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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