SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f937e80a1fe09cba3fb0117609ca0f1a5295113dad7dac7a98ec6ffbddcabae' 
  AND token = 'Tq0cDGQGyh4qqn4rBSBYFEV8/y7IIFArppKBPXC0jac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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