SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f7aa2a078c318d4f538aa9580e1f4b594e4181254d201b969bb9498b2fd19b9' 
  AND token = 'BSCbyftKhpeoyvSefhTM5WMZwbeTwsttvLG01y/QoBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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