SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aad8aadc207a2a7c66e80719cf4d835f16aee8686340a72a6aec2d06e3fe99e1' 
  AND token = 'FDhTntKxthCytGhyRKeN0fAJCP34OXSZjbDFzn20Qfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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