SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '427a9310c0d97e3884592cfdf7df2144c582782794b7c0640dc665fdd504cfda' 
  AND token = 'b5hKEvsShyvgW5Uoiw4iT4J290I4gO4ToFW2WJP1c4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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