SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7143681e2109ff9fae58304798b2896fc994332bceb2447d00624846b7185d6' 
  AND token = 'i2Qyt8ZGe4bLh7MbQjOzKgADfjAD0iXsFJ/QII+zlvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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