SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffb5daecf97ba85a400fec2b54bdb6fcd0f0ac52de098962927f150b8e7e79fb' 
  AND token = 'vj0WlWbRKStPsdfRS2R3FCsapnWSKtSyKuT3DMdDGN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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