SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b105ce1e83ae56a47237acc8a5064c732c5403b1f8880cbd992fc436b4b2d3a5' 
  AND token = 'E1ByscnSgBr41BVDskYyLi+lOMCiUT9FKQzdGSO2qME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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