SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ad5e3021549d67f5740e6dd197f80c7e3c0d4812a13e78cfee820777916dc796' 
  AND token = 'ryBXwLmSH2EmDWa4uDbc22aKdlZwGoFNyLLt8VJBu1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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