SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1da8ec00cb35bbaca60e88fac30ceda0d17b92fb1d1b55017b4d67efade88a0e' 
  AND token = 'xYfVHWaCaXSXfCrWLnoyuED8wE0ECv/7YJjF4h0zpNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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