SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f116b8df125be2b8d8a0af74fc550f23931d17375f77239c3cf8a50961c5b936' 
  AND token = 'Ai3pp0lzGm9EXBBnYTa9DEqXjvC/hagtZyJmr/B5Ieo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}