SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '49e25a9a8d0a94e337d4df5d0f0a3d008d502abacdb84281515afc1195d4d175' 
  AND token = '6OLJlTORiP8wpgewuo763LLldhpWAnxorAF6u5FXL1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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