SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7950cded743a94c09949cda51da4d4829ad8fa4af06c4acc1dee8ba09e318f07' 
  AND token = 'j2q0BfygrhL6SSY2lw+Z1ezEDymcuzXGgFKyf/lckaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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