SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dd89b7067ee105bf9a35a7348cd0e5899f07f592adca5b7d605819460b14286' 
  AND token = '+wrW1R0IkMbJA4nAdw+L9HcsuQvhGpE9JMZpfoqk1Kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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