SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72ea465b2eb52adc910d099d486e165869e3749ccca354a3a98c48370907a45b' 
  AND token = 'TgyniZeDd+lOfXYEOuctNSJVG4wI2pz/MIz8Ji7+PCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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