SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e28f9ca0ec3fb9710d69e2d17bf9464a6190b81069506251ea937e225ea4a34b' 
  AND token = 'eTar63vrrk7F+zfc0tGmVaGZaBKnR1Q6H4jvE+wqWOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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