SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9af2547f72988e60b1418ad8b814f5cf14ccfb1affc9543132abc8e8bd310e3' 
  AND token = '5rCBGsFnmIkymBMLWAudFFhcAMKezjnczT7I3i+RXMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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