SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36075ca627bdef486965d1cfeb607438095317407bfdfc56fd1dce12e88e17f9' 
  AND token = 'OXRWUctg+R3Tbq1VCKHa++wDBKqeIlqbUex9vWn0QXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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