SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd31fa9bc97b023a26f76b0f5a2216fe0462907c10e4ee390e74835d119b95f7d' 
  AND token = 'Jv7YwdPPdvaOXh6jicZAIKnvQG+1uHm48bpRMT6QPNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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