SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71c4385f161bb51d9a809cb1afbbebb3ba22630f37161095d9143252b850bb9e' 
  AND token = 'd892mxkXQRqweYlqqP3x0kmi+Rnyn/00jmR/ka+TMk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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