SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c150de0c9ffb97bd9353e87d05f1c31939f0e8bf0f5a75d74688193c5b930f3' 
  AND token = '3boC6jBR1v5/emmMgy3ckVa7FdA8tBb18K2s1sd2J0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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