SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf7591538ef847ac1042c9173fe34458a2b0638ce26fd4a168f461a62377997b' 
  AND token = 'Zgq918gAomIEMckuZ7GatmAHGP1U3KTsP1XuJPb819A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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