SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd3ebb93bd41aa4b7115ab9955e15c1cba5adc32bee605d9beef1805f081448a' 
  AND token = 'gnccJKwyz5fjxAfj1eCBqPsJyQuPUQcH8kz6KsLR7OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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