SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4720a6ab932d252e6ca6eb1803f98d8face261432de742ba54c24ad4accb4a9a' 
  AND token = 'GHAI1IfsLjeAJmbUp8Hhun3YmoXdqL0n+dbLIfYwQUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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