SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b37ed0ad666f2372a28398b72e236246e0af1aed1fbbaf5d1a2f2aa37d39d8af' 
  AND token = 'LO6XoScCUVV3B1DHoIN6v9Hl3Jlq2ip5EekcBfDO58Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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