SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f27d5b4374558c0ce10c7cfb64b112d74b83b1da162b393cfdcd3f4c59fc9d' 
  AND token = 'ZmRI7MwX2irnGGCfv+4JaRV6MmWsQJcjEAreOoDLTqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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