SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cfdca3b0ed9b4a7026d999e8aaab767fb6af885dc8293ded6d6032e8d0b8145' 
  AND token = 'uGqYlCsBJuvLa9221GBEF8IMf4TIleRXcEnWSygYgZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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