SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2e9924319fa445a7c01bfc9d129946de0ceff7c76c4fd3db6d7db6c7bc25e47' 
  AND token = 'qJ68AR4TShvRGaXTulphX++nzmEhJ/Gm8DtrAJsLVZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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