SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57184332b47efe855d64ca4c2d82c6aba1832737ec1ff92d1593af9a356f76b1' 
  AND token = 'Q/r3oRvphsjT58ZOYQ3Cr7WDX3WOzyzKmXoMuxE4RZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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