SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aebf4e40d1622b5d151bb233f2e0379a2e1952982f251f8cd52f671790cb875' 
  AND token = 'ot/CS3E4h0bPVpLSWYm+t40/gMqsARazqRHOBw/F+yM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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