SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14b212ac4727a22f57ef6b34f68d1640f38d2ecf740617646dd09116767d5351' 
  AND token = 'kuAJ/4BZCxRd27AhSoL2YXun/nCoaJwZm2DnjbzN8GI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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