SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6381a094753c6108f98592d417a089d429a574053cef48a316c7129e88ea1eec' 
  AND token = '+E8pr/j+3fq4E2P+Gp6IbYrzvG0uLPlH5zVKMflyLDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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