SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '975a464803dd952f5312914be03bc895a7b33f358ff87f8ad5c42d6df28b452b' 
  AND token = 'uVeeDFZ8VLqoH8fZZ/RvYMRdnbZdY5uJUKJdYWMuzZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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