SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c335f5bd8ae1151cdb0c2fc883d60a849ad8490ede71f6246006d56d1c7d644f' 
  AND token = 'L8KXJVJym86o3/4dkcmDzwp4/PhI1E+MYSLaqT3AFbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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