SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2eb4d776808e185e55ec17fc7fe90cb306bc2a36ca6012f61d6378a988c5412' 
  AND token = 'SB5L1mDE2epoG3JfQFPOdwfuAWMrokzU4oTneSvcFhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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