SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '27934a1993d6d80bf48e5561dac43be64b5179d6e4a3cbf728bd6984047f244a' 
  AND token = '7Pfeb+lM3YYGKJmTrj34Yqz4UzrRLdZiZSO1S8AoK+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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