SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5741a54ae0f9bfddcb3f7a48ade9a52eaf081b1d9f75bf2f23b10ced8a694c22' 
  AND token = 'dOYLtMpqBRaqjtCiUL7SrkjOJrAZvni1hOfjAvcc+i8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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